I am not getting the background displayed on most sites and layout of some is wrong
On all websites the background is not displayed in Firefox. Sometimes garphics are missing or wrongly displayed. There are also some websites where the layout is displayed just plain wrong. It has been suggested, when I have sent screenshots to the website owners, that Firefox is not interpretting CSS correctly.
Wšě wotmołwy (5)
Make sure that you allow pages to choose their colors and that you haven't enabled High Contrast in the Windows Accessibility settings.
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).
- Don't make any changes on the Safe mode start window.
- https://support.mozilla.com/kb/Safe+Mode
If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.
- Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
- Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")
Many thanks for your valuable advice. Just before I saw your reply I had an off-line conversation with a friend who suggested looking at user preferences which we did through about:config. There did not appear to be anything obvious, BUT I did make a change to one user set item then reset to the previous value. Restart Firefox and everything was fine! No, we don't understand either, but here's a guess. Somehow something in there became corrupted and forcing a resave of the data put it right. Maybe it became corrupted when windows froze (urghhh). As you suggested it is quite probable that using Safe Mode with Reset All User Preferences would have the same effect. I am very appreciative of your prompt advice - thanks.
Roger
You're welcome.
Do you still remember which pref you needed to change?
Sorry I don't. I was really looking to see the change mechanism. All I can say is that it was a boolian user pref which I changed then put it back again. Everything should have been at the default settings anyway as I found Firefox worked worked fine as is. I hadn't even added any plug-ins.
You can set a global default font (zoom) setting with both extensions.
Did you look in their options via Tools > Add-ons > Extensions ?